Bending roller for drawn sheet glass



March 10. 1925.

J. A. EEECE BERDING ROLLER FOR DRAWN SHEET GLASS Filed Fe'nQ F924;

T 8 WM G 1 N R r EAWU 1 I v T N T E \W A Patented Mar. 10, 1925.

UNI-TED STATES 1,529,274 PATENT oFFic-E.

JOSEPH A. REECE OF TOLEDO, OHIO, ASSIGNOR TO THE LIBBEY-GWENS SHEET GLASs COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO.

BENDING ROLLER FOR DRAWN SHEET GLASS.

r4 Application filed February 4, 1924. Serial No. 690,890.

To all whom it may concern:

Be it known that I. Josnrrr A. Rnncn. a citizen of the United States, residing at Toledo, i the county of Lucas and State of Ohio, ave invented new and useful improvements in Bending Rollers for Drawn Sheet Glass, of which the following is a specification.

This invention relates to improvements in the art of drawing sheet glass. and more particularly to an improved form of bonding roller about which the plastic glass sheet is deflected from one plane into an other.

In the system of drawing. sheet glass disclosed in the patent to (Tolburn, 1.248.809. granted December 4, 1917, a. sheet of glass is drawn vertically upward from a shallow pool of molten glass. and then while still plastic is bent about a cylindrical roller into the horizontal plane where it is flattcned and carried away through a leer as a continuous strip or ribbon of glass. In order to continuously maintain the width of the sheet. and otherwise improve the quality of sheet produced, each edge of the sheet directly above the molten source passes between a pair of cooled, knurled. rollers. which are positively driven at a peripheral speed considerably less than the linear speed at which the sheet is drawn upward. These cooled rollers grip and hold back on the edge portions of the sheet 'and' serve to stifien and place an added tension on these edge portions. the result being to keep the sheet to a uniform width." The edge portions of the sheet of glass will be roughened and somewhat thicker than the main cen tral portion which will have smooth hi ghlv polished surfaces and be of a uniform thick ness.

Since the edge portions of the sheet are initially retarded by the knurled rollers. the different portions of the sheet will travel at difl'erent speeds in their vertical run up to the bending-roller. All portions of the sheet should pass around the the roller at about the some linear speed, but in order to attain this speed the cooled edge portions, which are given delayed start, must travel faster than the central portion'during this vertical run. Due to this'initial variation in speeds between the edge portions and the central portion of .the-sheet and the fact that the edge portions are cooler and usually thicker than the central portion, there will sometimes be a difference in linear speed between the edges and the central portion while the sheet is passing about the bending roller. This will necessitate slippage of some portions of the sheet on the roller surface and there will consequently be a liability of scratching or wrinkling the sheet during this bending operation.

According to the present invention that portion of the bending roller which carries the main central portion of the sheet is made in the form of a freely rotatable sleeve set into the body of the bending roll proper. The edge portions of the sheet are su ported by, and in driving contact with, fixed cylindrical portions of the roll at the two ends of the central sleeve. Thus, the central portion of the sheet is allowed to proceed at a somewhat different rate than the edge portions. during the. bending operation. This will relieve the sheet from any undue s rains at this point and will greatly diminish or eliminate the scratching and \vrinl-tling of the sheet referred to above.

The objects and advantages of the invention will he better understood. from the following d tailed description of certain approved forms oi the apparatus.

in the accompanying drawings:

Fig. 1 is an elevation of that portion of the sheet-orawing mechanism comprising the improved bonding roller, the receptacle for the pool of molten glass being shown in transverse vertical section.

Fig. 2 is a central vertical section on an enlarged scale through the bending member.

Fig. 3 is an elevation of one end of the roller. showing auailiary driving rollers 00- operating with the fixed end portions of the bending roll.

The glass sheet 1 is drawn upwardly from the pool of molten glass 2 in receptacle 3. Af er the sheet has been drawn upwardly till it has assumed approximately its final sheet form, but is still somewhat plastic, it is bent about the bending rollen 4 into the horizontal plane. The sheetis then drawn away through suitable drawing and flattening mechanism and thence into the annealing leer. The drawing and flattening mechanism is not here illustrated, but may be of the type disclosed in the Colbum patent referred to hereinahove. Earh edge of the sheet adia 'rnt its sourre passes hetwc'n a pair i hnnrh d or ronghcmd X'Pllri's indicated at Those rollers are internally (tooled, and are slowly driven at a periplr oral speed considerably less than the linear speed at which the sheet is drawn upwardly. These rollers and the driving me hanism therefor. are described more in detail in the Colburn patent referred to shove. The edge portions 6 of sheet l will he marr d or roilghened by the gripping action of roll ers 5, hut these edges are eventually cut away and discarded. These edge portions 6 will draw somewhat thicker than the main body portion of sheet 1 and will he cooler and stiller due to the contact therewith of the internally cooled rollers 5.

The entral portion of the bending roll 4 is rednred in diameter as at 7, and mounted on this redured portion is a cylindrical sleeve 8. having the same outer diameter as the end portions of bending roll 4. This sleeve 8 is made of some suitable alloy such as Monel metal or nichrorne. (-apahle of taking and maintaining a high polish on its outer rvlindrical sheet-supporting urface 9. The main portion of the iwndintf i ll 4 may he ronstructeijl in two swirl ions s reu'ed t gether as at 10 to permit the ii-wilful! oi" the sleeve 8 upon the redin-ed portion 7 =t' the roller. Prcferahlv roller l 'tlllli fs uwh as indicated at 11 will h used i iroi-n the sleeve F4 and the portion 7 of lllt' lien lin roll on whirh it is mounted. The port'ioi' of th bending: roll 4 ailiacent i-iihcr rod of sleeve R are grinned or lfllllllwl as indi rated at 12(1) positively grip the r ughen d edge portion 6 of the glass sheet and hold the sheet agains lateral contracti n while passing: aroiind the bonding nn-mher.

'hile means are usually provided to (h iv the roller 4 to assist in boginnin; the sliLOtdrawing operation. ordinarily this roller 4 turns idly in roller bearings \vhcn thidrawin;' operation is once under way. The roller 4 will then be rotated by the thickened edge portions i; of the sheet which engage with the grooved ends 12 of the roller. Since the sleeve 8 which carries the main wntrnl portion of glass sheet 1 is freely rotatable with relation to the end portions 12 of r ller 4. this central portion of the sheet will be allowed to I'Otfltt either faster or slower than the edge portions, thus relieving the sheet from any undue strain: and eliminating the necessity for Slippzlgn of the fire-polished sheet surfaces upon the sheet-carrying surface 9 of the roller.

If the bending member 4is to be used as a positive drawing member in lifting the sheet from its molten source, auxiliary driven rolls 13 will preferably be added. These rollerg which are mounted on a driven shatt 14, ha egrooved or knurled surfaces 15 whieh on aue the upper side of the edgiportivns o? the sheet above the edge rarrvinp portions 12 of roller 4 thus ositively gripping: these 'dgeport-ions of the sheet lit-tween the two di iving surfaces. A before, the main entral body of the .slltfl, is not poslllVOly drivin, but is supported during the bending operation upon the freely rotatable sleeve 8 lilllllsl 1. In an apparatus for drawing sheet glass, a roller about Whirl) the sheet is deflected from one plane to am ther, the roller comprisingseparate end and central portions adapted to travel at d fi'erent peripheral speeds.

Z. In an apparatus for drawing sheet glass, a roller ahout whirh ihe sheet is defleizted fr m one plane to 3111 ther, the roller having :1 Continuous cylindrical sheet-carrying Slll'ffltf', OYllIHlSillJ separate end and central portions adaptml to travel at different peripheral speeds.

3. In an apparatus for drawing sheet glass Continuous cylindriral roller about whi h thisheet is deflerted from one plane to another. i-oinprising portions adapted to support and draw the edge portions of the hort and a troelv rotatable portion for snpprlin; tho mi in central portion ofithe s eet.

4. In :in ap niratus for drawing sheet glass. a roll r :ilioiit which the sheet is del 'ii-d from one plane to another, the Toilet i-oinprising rin'l portions for rarryin" the i-iige portion of the shoot. and a freely rotntnlilo intermediate portion.

5. In an apparatus for drawing sheet ;{lfiss a roller about which the sheet is ilellcrtrd from one plane into another. the roller manprisin; end portions for carryll'lLf the edge portions of the sheet, and a lot) freely rotatable sleeve ionrnaled on the (en- 4 tral portion of the roller.

6. In an apparatus for drawing, sheet glass. a roller about whirh the sheet is deflected from one plane into another, the roller romprising end portions for carrying the edge portions of the sheet. and a freely rotatahle sleeve ionrnzilod on the central portion of the roller. and having a cylindrical sheet-(arming sin-are of the same diameter as the end pi rtions.

7. In an apparatus for drawing sheet glass. a roller about which the sheet is defim-trd from one plane into another, the roller comprising end portions for carryin; the edge portions of the sheet, and a freely rotatable sleeve iournaled on the central portion of the roller. and roller bearings between the sleeve and roller.

8. In an apparatus for drawing sheetglass. a roller about which the sheet is deflected from one plane in another, the roller comprising and port us for carrying the edge portions ofthe sheet, and a freely rotatable intermediate portion, in combination with a air of driving rollers engaging the opposite faces of the edge portions of the sheet.

9. In an apparatus for drawing sheet glass, a roller about which the sheet is deflected from one plane into another, the roller comprising end portions for carrymg the edge portions of the sheet, and a freely rotatable sleeve journaled on the central portion of the roller, and having a cylindrical sheet-carrying surface of the same diameter as the end portions, in combination with a pair of driving rollers engaging the opposite faces of the edge portions of the sheet.

Signed at Toledo, in the county of Lucas and State of Ohio, this 25th day of January, 1924.

JOSEPH. A. REECE. 

